lantiq: fix PCI_DEVICE_ID_LANTIQ_PCIE

lantiq: fix PCI_DEVICE_ID_LANTIQ_PCIE

It's not necessary to define PCI_* if pci_ids.h is included a few
lines above.

The change to pci_ids.h doesn't look intentional to me, especially
since the former value is added to the top of ifxmips_fixup_pcie.c.

Both changes were introduced with the kernel 4.1 support patches and
were not present in the 3.18 patches.

Signed-off-by: Mathias Kresin <openwrt@kresin.me>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47996 3c298f89-4303-0410-b956-a3cf2f4a3e73